This invention relates to “means to assemble,” more specifically to apparatus for feeding plural work parts from plural work sources without manual intervention, and even more specifically, to apparatus for stressing work parts beyond elastic limits. Within these categories of technologies, this invention relates to mechanisms for feeding loops or ties in series into metal clip attachment apparatus, known as clippers.
Numerous patents disclose clip attachment apparatus or clippers. Broadly, these devices attach U-shaped metal clips by deforming the legs of the clips, to place them around such materials as gathered casing for comminuted materials, to form sausage chubs and the like. Example patents include U.S. Pat. No. 5,077,955 issued Jan. 7, 1992 to Evans, U.S. Pat. No. 5,269,054 issued Dec. 14, 1993 to Poteat et al. These are incorporated by reference, and U.S. Pat. No. 6,524,178 issued Feb. 25, 2003 to Fässler et al.
It has been known for some time to be desirable to insert loops or ties under the crowns of the clips so that the loops or ties may be attached to the gathered sausage casing materials or other material simultaneously with the attachment of the clips. The clipped loops or ties may be used to carry, otherwise support or hang the products that are formed and clipped. A variety of loops or ties are known, including those of U.S. Pat. No. 4,720,010 issued Jan. 19, 1988 to Bertram, and U.S. Pat. No. 5,755,022 issued on May 26, 1998 to Whittlesey. These are incorporated by reference.
The '022 patent to Whittlesey also discloses a desirable mechanism for feeding the string loops of that patent into clip attachment apparatus. The mechanism is two-stage, with loops removed from a tape carrier in a first stage, and then transported to the clipper in a second stage. More specifically, referring to FIG. 1 of the Whittlesey patent, starting at the upper left and following loops around, loops start on a tape on a reel 62. They pass over rollers 64, 68, and 70. A plunger 80 pushes the loop end of a loop, as best seen in FIG. 4, such that an arm 82 mounted around a corner can swing by, and snag the loop. The loop is removed from the tape, completing a first stage. Referring to FIG. 8, the snagged loop is pivoted around on the arm 82. Referring to FIGS. 9 and 10, the loop is positioned as in FIG. 9 with the arm 82 retracted, to be caught and moved by a bracket 130 on a belt 88 around to a final position as in FIG. 10. As in FIGS. 10 and 11, the tie or knot end 58 is forward. As in FIG. 11, the tie end enters a clipper window 52, and as a clip moves by, the loop is driven with the clip to be fastened with the clip 40, as in FIG. 12.
Other patents similarly disclose loop and tie feed mechanisms for clippers. These include U.S. Pat. No. 5,067,313 issued Nov. 26, 1991 to Evans, U.S. Pat. No. 5,203,759 issued Apr. 20, 1993 to Torres et al., and U.S. Pat. No. 5,269,116 issued Dec. 14, 1993 to Roberts et al.
Reliability is always a concern of designers of mechanisms for feeding loops or ties into clippers. High reliability for automatic loop insertion is a goal. Another goal is accommodation of loops manufactured with wide dimensional tolerance ranges. Any commercially desirable mechanism must also be as inexpensive as possible.
While the existing products, machines and methods of the “loop feeding art” and the separate “clipping art” have great value, especially those from Tipper Tie Inc., the frontier of technology is ahead of them, to be advanced further by inventive efforts.